Basic azo dyestuffs



United States Patent BASIC AZO DYESTUFFS Rudolf Ruegg, Basel,Switzerland, assignor 'to Ciba Limited, Basel, Switzerland, 21 Swissfirm No Drawing. Application May 6, 1955, Serial No. 506,657

Claims priority, application Switzerland May 13, 1954 9 Claims. (Cl.260-152) This invention provides now basic dyestuffs which, like thedyestufi of the formula (1) HaC CH3 r Q H 1 CCH=N-N T 021 1 are freefrom sulfonic acid and carboxylic acid groups. The new dyestuffs existin two forms and correspond to the formulae (2a) and (2b), (2a)representing salts and (2b) representing the corresponding free bases:

. ilk l Anion n1 O=CHN=NR2 Alkyl In these formulae R represents abenzene or naphthalene radical fused on to the heterocyclic ring at thepositions indicated by the valence bonds, Z represents a sulfur atom oran Alkyl group and R represents a benezene radical containing a singlenitro group in ortho-position to the amino group or an anthr'a'quinoneradical bound in the l-position to the NH group or a radical of theformula Alkyl in which Z and K, have the meanings given above, and Rrepresents an anthraquinone radical bound in a-positions to thetwo NH gr oups.

2,815,338 Patented Dec. 3, 1957 ICC By means of an alkali, such as forinstance ammonia, the salts of the Formula 2a can easily be convertedinto the corresponding bases of the Formula 2b.

The invention also provides a process for the manufacture of theaforesaid dyestuffs, wherein a diazo-compound of amononitro-orthoarnin'obenzene or of a laminoanthraquinone is additivelycombined on one side or a tetrazo compound of anoum-diaminoanthraquinone is additively combined on both sides with abase of the formula z \C=CH2 A Alkyl or such diazo-compound is condensedon one side or such tetrazo compound on both sides with a salt of theformula R1 C-CHa .Alkyl Anion in which formulae R represents a benzeneor naphthalene radical fused on to the heterocyclic ring at thepositions indicated by the valence bonds, and Z represents a sulfur atomor an Alkyl group, and wherein the starting materials are free fromsulfonic acid and carboxylic acid groups.

As starting materials there are advantageously used tetrazoor moreespecially diazo-compounds of the above kind, in which the diazotizedamino groups are bound to carbon atoms which are vicinal to a carbonatom bound to a hydrogen atom, that is to say, diazo compounds of1-amino2-nitrobenzenes unsubstituted in the 6-position or ofa-amino-anthraquinones unsubstituted in a vicinal ,8- position, ortetrazo compounds of am-diaminoanthra- Alkyl quir'rones unsubstituted invicinal B-positions.

1-amino-2-nitrobenzene, 1-amino-2-nitro-4-methylbenzene,1-amino-2-nitro-4-methoxybenzene, 1-amino-2-nitro-4-chlorobenzene,1-amino-2-nitro-4-acetylaminobenzene,1-amino-2-nitro-4dimethylaminobenzene, 1-amino-2-nitro-4-phenylbenzene,l-amino-2-nitro-4-(N:N-methylacetyl) -aminobenzene,l-amino-2-nitro-4-cyclohexylbenzene, and 1-amino-2-nitro-5phenylaminobenzene The anthraquinone compounds which may be used asstarting materials may contain, in addition to the diazotized aminogroups, further substituents, for example,

those mentioned above. There may be used, for example, diazo compoundsof the following aminoanthraquinones:

l-aminoanthraquinone, 1-amino-4-methoxyanthraquinone,l-amino-4-hydroxyanthraquinone, l-amino-4-chloranthraquinone,

128-, 1:4- or especially 1:5-diaminoanthraquinone.

The bases of the Formula 4 also serving as starting materials in thepresent process and the quaternary socalled cyclo-ammonium salts of theFormula 5 derived from these bases, contain as a member of theheterocyclic ring either a sulfur atom or a carbon atom bound to twoalkyl groups. There are advantageously used compounds, wherein the alkylgroup bound to the nitrogen atom, and when Z represents an group alsothe alkyl radicals of the latter group, contain only few, for example,at most four carbon atoms. Especially important are bases and salts ofthe formulae in which n represents a whole number not greater than 2,and advantageously 1. The radical R may be a naphthalene or benzeneradical fused on to the heterocyclic ring in the manner shown and maycontain in the condensed aromatic radical substituents, for example,those mentioned above in connection with the diazo-compounds.

As examples of bases of the Formula 4 there may be mentioned thefollowing compounds C=CHs 1-methyl-2-methylene-benzthlazollne C=C H I C1H5 1-ethyl-2-methylene-benzthlazollne 17-dimethyl-5-chloro-2-methylene-beuzthiazolina 1 33-trimethyl-2-methylene-indoline HzC CH;

5-methoxy-1: 3: 3-trimethyl-Z-methylene-indollne 5-ethoxy-1 33-ttlmethyl-2-methyIene-lndollne HtC\ /CHa 0 NEC- CHa

5-cyano-1: 3 3-trimethyl-Z-methylene-indoline (obtainable by condensingpara-cyanophenylhydrazine with ethylmethyl ketone and reacting theresulting 2: 3-dimethy1-5-cyano-1ndole with methyl bromide) (J -CH:

1-ethy1-3 3-d1methyl-2-methylene-indo1ine H502 Cz'Hs l GIHI 1 33-trlethyl-2-methylene-lndollne 'I-chloro-l 38-tr1methyl-2-methylene-lndo11ne 1 3: 3-trimethyl-2-methylene-67-benzo-indo1ine 1 3 3-trimethyl-2-methylene-4 -benzo-indoline5-methyl-1 3 3-trimethy1-2-methylene-indoline The bases to be used asstarting materials in the present process are largely known, and theycan be made by methods in themselves known. The bases may be convertedinto salts of the Formula 5 by means of acids. Any desired acid may beused, but it is usually of advantage to use simple easily accessibleacids, for example, hydrochloric acid, sulfuric .acid or acetic acid.

As stated above, in the present process diazo-com pounds ofmononitro-ortho-aminobenzenes or of l-aminoanthraquinones ortetrazo-compounds of aza-diaminoanthraquinones are reacted with bases ofthe Formula 4 or salts of the Formula 5. Accordingly, the diazocompounds contain in a position vicinal to the diazotized arnino group asubstituent imparting a strongly negative character, that is to say, inthe case of diazo compounds of the benzene series, nitro groups and inthe case of diazoor tetrazo-cornpounds of the anthraquinone series,carbonyl groups. As diazo-compounds there may be used not only diazoniumsalts such as diazonium chlorides or sulfates, but also antidiazotatesor if desired diazoxides.

The reaction of the diazo compounds with the bases of the Formula 4 orwith theusalts of the Formula 5 is carried out with advantage in anaqueous and advantageously an acid medium.

It is usually desirable to buflfer any excess of mineral acid during thereaction by a suitable addition, such as sodium acetate to the sodiumbicarbonate or pyridine. In some cases, especially with diazo-compoundsof aminoanthraquinones, it may be of advantage to carry out the reactionin an organic solvent, for example, glacial acetic acid, benzene oracetone. In other respects the reactions are carried out under theconditions hereinbefore described, that is to say, in such manner thatonly one molecular proportion of a diazo compound of the kind describedabove couples with 1 molecular proportion of a base of the Formula 4 orof a salt of the Formula 5 and only one molecular proportion of atetrazo-compound couples with two molecular proportions of the base orsalt. It bases or salts are used which contain as Z a carbon atom boundto two alkyl groups, the danger of the react-ion taking an undesiredcourse is very small. It, on the other hand, Z represents a sulfur atom,it is necessary to avoid an excess of the diazo compound, as otherwisetwo molecular proportions of the diazo-compound may easily combine.additively with one molecular proportion of the base or two molecularproportions of the diazo 6 compound may condense with one molecularproportion of the quaternary salt of the base.

The new dyestuffs of the Formula 2 are suitable for dyeing and printinga very wide variety of materials, especially polyacrylonitrile fibers.These fibers may, for example, be composed solely of polyacrylonitrileor of copolymers which contain a substantial amount of acrylonitrilecopolymerized therein, or mixtures of different polymers containing asubstantial amount of polyacrylonitrile.

Dyeing is usually carried out with advantage in an aqueous medium. Thedyestuffs of the Formula 2 are usually sufiiciently soluble in water toenable them to be used for dyeing in the form of aqueous solutions. Theproducts which are sparingly soluble in water, and cannot be appliedfrom aqueous solution, may be applied by the dispersion dyeing processcustomary for cellulose acetate artificial silk and nylon, in which thedyestufi is dispersed by means of a suitable dispersing agent, forexample, with a soap, a-benzimidazole sulfonic acid having a higheralkyl radical in the [.L-IJOSifiOH of the imidazole radical or apolyglycol ether of a fatty alcohol of high molecular weight, and thedyestufi is used in this dispersed form.

In some cases it is of advantage, before adding a sparingly solubledyestufi to the dyebath, to dissolve it or make it up into a paste asuniformly as possible in a suitable, and advantageously water-miscible,organic solvent or diluent.

It is generally desirable to carry out the dyeing in a weakly acid, forexample, acetic acid, bath at a raised temperature. For example, thedyeing process may be commenced at a moderately raised temperature ofabout 4070 C. and finished at the boiling temperature of the dyehath.Especially valuable results are often produced by dyeing under pressure,that is to say, in a closed vessel at a temperature of -130 C.

The above remarks with regard to the various methods of dyeing applyalso to the printing of polyacrylonitrile fibers.

The dyeings so produced are distinguished in general by their puretints, and above all by their very good properties of fastness. Thus,for example, dyeings of very good fastness to light are obtained, andthe resistance of the dyeings to treatments with alkalies, for example,washing in an alkaline medium for long periods, is surprisingly good.The dyeings also possess good fastness to perspiration. Especiallyadvantageous, also, is the property of these dyestuffs for reservingwool fibers present .in the dyebath, so that these fibers can, ifdesired, be

dyed in a further bath with an ordinary wool dyestufi.

The dyeings obtainable in accordance with this invention may, ifdesired, be subjected to various after-treatments. Thus, for example,such a dyeing may be soaped at a moderately raised temperature orsubsequently steamed without being intermediately dried. Moreover, asubsequent heat treatment at a temperature above 100 (1., for example,at -130 C., may be of advantage. The following examples illustrate theinvention, the parts and percentages being by weight unless otherwisestated and the relationship of parts by weight to parts by volume beingthe same as that of the kilogram to the liter:

Example I 13.8 parts of l-amino-Z-nitrobenzene are suspended in the formof a fine powder in 100 parts of water and'lOO parts of ice, and then 25parts by volume of a 4N-solution of sodium nitrite are added. 30 partsby volume of hydrochloric acid of 30 percent strength are then rapidlyadded, in one portion, while stirring. The whole is stirred for afurther 15 minutes at 0-5 C., and filtered, if necessary, after theaddition of aminosulfonic acid. 17.5 parts of 1:3:3trimethyl2-methylene-indo1ine of the above Formula 11 are dissolved in 200 partsof ice water with the addition of 15 parts by volume of hydrochloricacid Ha O\ Ha OgN is filtered off and washed with 500 parts of icewater. When dry, it is a red-yellow powder which dissolves in water witha red-yellow coloration and dyes polyacrylonitrile staple fibers from anacetic acid bath full red-yellow tints of good fastness to light.

By using instead of 13.8 parts of l-amino-Z-nitroben- 'zene, 15.2 partsof 1-amino-2-nitro-4-methylbenzene or 17.3 parts ofl-amino-2-nitro-4-chlorobenzene, there are obtained dyestuffs havingsimilar properties.

By using 16.8 parts of 1-amino-2-nitro-4-methoxybenzene or 18.2 parts of1-amino-2-nitro-4-ethoxy-benzene or 19.5 parts of1-amino-2-nitro-4-acetylamino-benzene, instead of 13.8 parts ofl-amino-2-nitrobenzene, dyestuffs are obtained which dyepolyacrylonitrile fibers from an acetic acid bath red orange to scarlettints which are fast to light. The dyestuif obtained from 1-amino-2-nitro-4-acetylamino-benzene has the formula By using 18.1 parts of1-amino-2-nitro-4-(dimethylamino)-benzene, instead of 13.8 parts ofl-amino-Z-nitrobenzene, there is obtained a dyestufi which dyespolyacrylonitrile fibers fast blue tints.

From the dyestuff prepared as described in the first paragraph of thepresent example the free base may be obtained as follows:

30 parts of the last-named dyestufi are dissolved in 1000 parts ofboiling water with addition of parts by volume of hydrochloric acid of30% strength. The solution is filtered in the hot in order to remove anysolid impurities and then cooled to 30 C. by the addition of ice. Atthis temperature concentrated aqueous ammonia is added to the solutionuntil a pH value of 10 is reached. The free base precipitates in reddishorange flakes and is then filtered off, washed with cold water and driedin vacuo at 60-70 C. It forms a reddish orange powder melting at 153 C.

Example 2 7 parts of powdered sodium nitrite are introduced in smallportions at 0-5 C. into 120 parts of concentrated sulfuric acid. Thesuspension is heated to 80 C. in the at 0-5" C. into a solution of 17.5parts of 1:3:3-trimethyl-Z-methylene-indoline of the Formula 11 in 200parts of ice water, and 15 parts by volume of hydrochloric acid of 30percent strength. In the course of one hour the bulk of the sulfuricacid is neutralized by the addition of about 300 parts of powderedcrystalline sodium acetate. The whole is stirred for a further 20 hoursat 0-5 C., and the dyestuff is then filtered off and washed with 500parts of water. The dry dyestutf which corresponds to the formula is abrown red powder which dissolves in water with a red-orange colorationand dyes polyacrylonitrile staple fibres from an acetic acid bath orangetints which are very fast to light.

By using instead of 22.3 parts of l-aminoanthraquinone, 25.3 parts of1-amino-4-methoxy-anthraquinone, there is obtained a dyestufi which dyespolyacrylonitrile fibers blue-red tints.

A red dyestufi having similar properties is obtained by using 11.9 partsof 1:5-diaminoanthraquinone.

Example 3 Into a solution of nitrosyl-sulfuric acid prepared asdescribed in Example 2 there are introduced at 30-40 C. in smallportions 23.9 parts of 1-amino-4-hydroxyanthraquinone, while stirring.In order to induce the diazotization there are then introduced at --10C. parts of ice, whereupon the temperature rises to 20 C. After a shorttime the brown solution is poured on to 300 parts of ice. The yellowdiazonium sulfate is filtered off, and then triturated with 300 parts ofwater, whereby it changes into the red diazoxide compound, which isfiltered off and washed with water until neutral. 17.5 parts of1:3:3-trimethyl-2-methylene-indoline are mixed with 75 parts of glacialacetic acid, and added to a suspension of the above diazoxide compoundin 1000 parts of glacial acetic acid at 1525 C., while stirring. After afew hours, parts by volume of a saturated solution of sodium chlorideare added to the dark red solution, and then the dyestufi is filteredoff and washed with water until neutral. The dried dyestufi' is a darkpowder, which dissolves in hot water with a blue-red coloration and dyespolyacrylonitrile fibers from an acetic acid bath fast bluered tints.

Example 4 22.3 parts of l-aminoanthraquinone are diazotized as describedin Example 2 and reacted in the same manner with 21.7 parts of5-ethoxy-l:3:3-trimethyl-2-methyleneindoline of the Formula 13. There isobtained a dyestufi of the formula which, when dry, is a brown-redpowder which dissolves in water with a red coloration and dyespolyacrylonitrile fibers fast red-orange tints.

,By using, instead of the diazo compound of 22.3 parts ofl-aminoanthraquinone, the diazo-compound prepared in the usual mannerfrom 16.8 parts of 1-amino-2-nitro 4-methoxybenz'ene, there isobtained'a dyestufi which dyes polyacrylonitrile fibers red tints.

By using, instead of 21.7 parts of 5-ethoxy-lz-3z3-trimethyl 2 methyleneindoline, 22.3 parts of 1:3 :3-trimethy1-2-methylene-6:7-benzo-indolineof the Formula 18, there is obtained a dye'stutf which likewise dyespolyacrylonitrile fibers red tints.

Example 5 27.5 parts of 1:Z-dimethyl-benzthiazolium methosulfate,obtainable from Z-methyl-benzthiazole and dimethylsulfate and which inits free base state corresponds to Formula 8, are suspended in 250 partsby volume of benzene, and then 25 parts by volume of sodium hydroxidesolution of 30 percent strength are added while stirring vigorously.After a few minutes, the benzene layer containing the methylene base isseparated and thoroughly miXed with the diazonium solution of 13.8 partsof l-amino-Z-nitrobenz'ene prepared in the usual manner, the mixingbeing carried out, for example, in a mortar. The resulting dye/stuffhaving the formula N Gri l is filtered off after a short time and driedat 40-50 C. It is a brown-orange powder which dissolves in water with ayellow coloration and dyes polyacrylonitrile fibers from acetic acidbaths pure yellow tints of good fastness to light. When wool is presentat the same time it is not dyed.

Example 6 A diazo-suspension prepared as described in :Example 2 from22.3 parts of l-aminoanthraquinone is filtered, the filter residue iswashed with Water and freed as far as possible from adherent water bypressing. The ,pre'ssed material is then suspended in 500 parts byvolume of acetone. 28.9 parts of 1-ethyl-2-methyl-benzthiazoliummethosulfate, which in its free base state corresponds to Formula 9, aresuspended in 500 parts by volume of benzene, and then 50 parts by volumeof sodium hydroxide solution of 30 percent strength are added, Whilestirring vigorously. After a few minutes the benzene layer containingthe methylene base is separated, and added rapidly and in one portion tothe acetone diazosuspension, while stirring. After a few hours thereaction mass is dried at ordinary temperature in vacuo. The dyestuff isdissolved in boiling water, filtered to remove sparingly soluble matter,and precipitated by means of a saturated solution of sodium chloride.When dry, it is a red powder which dissolves in water with an orangecoloration and dyes polyacrylonitrile fibers very fast yellow-orangetints.

Example 7 21.5 parts of l:3:3-triethyl-2-methylene-indoline aredissolved in 200 parts of ice water with the addition of 30 parts byvolume of hydrochloric acid of 30 percent strength. A diazonium solutionof 13.8 parts of l-amino- 2-nitrobenzene prepared in the usual way isadded dropwise in the course of one hour while stirring at to C. to theabove solution. In the course of some hours the excess hydrochloric acidis neutralized by the addition of about 150 parts by volume of a4N-solution of sodium acetate. After a few hours more, the formation ofthe dyestutf which proceeds very slowly is completed by the addition ofabout 50 parts of pyridine.

The dyestuff which is a dark brown resin is dissolved in the warm in acondensation product of a higher aliphatic alcohol with ethylene oxideand, after cooling, is triturated with an excess of amido-sulfonic acid.This dyeing preparation dissolves in water with a red-yellow colorationand dyes polyacrylonitrile fibers red-yellow.

, 10 Example '8 0.5 part of the dyestulf obtained as described in thefirst paragraph of Example 2 is pasted with 0.5 part of acetic acid of40 percent strength. The mixture is covered with hot water, the whole isboiled and combined through a sieve with an aqueous solution whichcontains 3-5 parts of acetic acid of 40 percent strength, 1-3 parts ofsodium acetate and 4 parts of acondensation product of ethylene oxideand commercial octyl alcohol. The volume of the dyebath so prepared ismade up to 4000 parts by volume. A well desized yarn ofpolyacry'lonitrile staple fibers is entered at 50-60 C., the bath israised to the boil in the course of 30-45 minutes, and then dyeing iscarried on for one hour as near to the boiling temperature as possible.'The yarn is then rinsed with cold water and, if desired, soaped for ashort time, for example, at 60 C. in a bath which contains l-2 parts ofsodium -heptadecyl-N benzyl -benzimidazole disulfonate in 1000 parts ofwater. The yarn is dyed orange, and the dyeing is distinguished by itsvery good fastness to light.

What is claimed is:

l. A dyestuif which is free from 'sulfonic acid and carboxylic acidgroups and in its free base state corresponds to the formula Alkyl inwhich R represents a member selected from the group consisting of abenzene and a naphthalene radical, said radical being fused on to theheterocyclic ring at the positions indicated by the valence bonds, Zrepresents a member selected from the group consisting of a sulfur atomand an Alkyl Alkyl group, and R represents a member selected from thegroup consisting of a benzene radical containing a single nitro group inortho-position to the N:N- group, an anthraquinone radical bound in the1-position to the N:N- group, and a radical of the formula in which Zand R have the meanings given above, and R represents an anthraquinoneradical bound in a-positions to the two --N:N- groups each Alkyl radicalcontaining at the most 2 carbon atoms.

2. A dyestufi which is free from sulfonic acid and carboxylic acidgroups and in its free base state corresponds to the formula Alkyl inwhich R represents a benzene radical fused on to the heterocyclic ringat the positions indicated by the valence bonds, the Alkyl radicalcontains at the most two carbon atoms and R represents a benzene radicalcontaining a single nitro group in ortho-position to the N:N--

group.

3. A dyestuif which is free from sulfonic acid and 11 carboxylic acidgroups "and in its free base state sponds to the formula Alkyl AlkylAlkyl in which R represents a benzene radical fused on to theheterocyclic ring at the positions indicated by the valence bonds, theAlkyl radicals contain at the most two carbon atoms and R represents ananthraquinone radical bound in the 1-position to the N:N group.

5. A dyestuif which in its free base state corresponds to the formulaAlkyl Alkyl 6. A dyestuff which in its free base state corresponds tothe formula 12 7. A 'dyestufi which in its free base state correspondsto the formula N I C 8. A dyestuff which in its free base statecorresponds to the formula 9. A dyestufi which in its free base statecorresponds to the formula H1c cm 0 HlCr-O- o- 0 (EB,

References Cited in the file of this patent UNITED STATES PATENTS2,464,785 Thompson Mar. 22, 1949

1. A DYESTUFF WHICH IS FREE FROM SULFONIC ACID AND CARBOXYLIC ACIDGROUPS AND IN ITS FREE BASE STATE CORRESPONDS TO THE FORMULA